Title:
Murphy’s Law in Left Anterior Descending Percutaneous Coronary Intervention
Introduction:
A 75-year-old woman with angina was referred for coronary angiography. She had a history of multiple co-morbidities including hypertension, hyperlipidemia, type 2 diabetes mellitus, obesity (BMI 39.9), ischemic stroke in 2014, hypothyroidism, obstructive sleep apnea, irritable bowel syndrome, and she is a former smoker (10 pack-years). Stress echocardiography one month prior was negative for ischemia but it was a technically difficult exam.
Left ventricular ejection fraction of 60-65% was measured by
echocardiography. Coronary CT demonstrated moderate lesions in the left anterior descending artery (LAD) and diagonal branches, CT FFR was measured in the LAD: 0.86, and Diagonal: 0.85.
Clinical Case:
Due to tortuous subclavian artery, it was difficult to engage the coronaries from radial access. Diagnostic angiography revealed a diffusely diseased, calcified LAD and no significant stenosis in the left circumflex and right coronary arteries. IFR in the LAD was measured 0.63 with two step-ups. Percutaneous coronary intervention (PCI) of the LAD was decided, and a workhorse wire (Sion Blue) was inserted to the LAD and a Samurai RC wire to the Diagonal. Predilations were performed in the distal and mid LAD followed by a 2.25x12 mm drug eluting stent (DES) implantation to the distal LAD. We repeated the predilations in the mid LAD and the lesion seemed to be expanding well. However, the second DES (2.5x34 mm) could not cross the lesion due to extreme calcification; the stent could not cross even using guide catheter extension. Then
we attempted to switch the guidewire, but Micro14 microcatheter could not cross either. Finally, with side-branch anchor the Micro14 crossed and the workhorse guidewire was exchanged to Wiggle wire. Repeated delivery attempt of DES 2.5x26 mm was performed, but the stent got dislodged, we tried to retrieve the stent with 1.0 and 1.5 mm balloons. The 1.5 mm balloon partially retrieved it, but could not be withdrawn into guide due to deformation. The decision was made to deploy the stent proximally and postdilate it with 2.75 mm balloon, the patient developed chest discomfort. Predilation of mid LAD again was performed and
eventually 2.5x28 mm DES could be delivered and deployed, followed by a 2.75x18 mm DES proximally. After postdilations with non-compliant balloons the final angiography revealed TIMI 3 flow and well expanded stents.
Discussion:
Non-invasive testing has limitations. Calcification and tortuosity hinder stent delivery and expansion. Vessel preparation is critical before stent delivery and deployment. If stent loss occurs and the retrieval is challenging: deploy or crush the stent. In case of dissection/acute closure: do not lose wire position.